Wireless communication networks have become increasingly popular. One form of communication network, a so-called WiMAX system, may be defined by a standard such as the Institute for Electrical and Electronics Engineers (IEEE) 802.16. This document uses terminology, including abbreviations, that is also used by the IEEE 802.16 standard for the sake of convenience, but is not meant to be limited thereby.
FIG. 1 is an illustrative example of a communication network 100. The communication network 100 may include a base station (BS) 102 that provides service to a cell area located around the base station 102. One or more subscriber stations (SS) 108, which may be mobile stations (MS), cell phones, laptops, and the like, may be able to communicate with the base station 102 when they are within the service area 110 of the base station 102. The communication network may also include one or more relay stations (RS) 104 to extend the service area of the base station 102 if, for example, the broadcasting range of the base station 102 is insufficient to reach a subscriber station 106 or a mobile station.
User data packets may be transmitted over the transmission path 114 between the base station 102 and the subscriber station 108. User data packets may also be transmitted between the base station 102 and the relay station 104 over the transmission path 112, to be retransmitted to the subscriber station 106 over the transmission path 116. User data packets may include items having various priorities for their delivery. The base station 102 and the subscriber stations 106 and 108 may include schedulers to schedule the items for transmission according to their priorities.